Mucociliary clearance (MCC) allows ventilation of graft particles that are displaced through a perforated Schneiderian membrane during maxillary sinus augmentation (MSA). However, it is very rarely confirmed by cone-beam computed tomographic (CBCT) images. It is not yet known how long the dislodged bone graft particles remain in the maxillary sinus or how quickly they are ventilated after MSA. The purpose of these case reports is to introduce tomographic imaging of ventilation of bone graft particles displaced through a perforated Schneiderian membrane after MSA. Four patients, who needed implant placement in the posterior maxilla, received MSA, during which the Schneiderian membrane was perforated but was not repaired. Therefore, some bone graft particles were dislocated into the sinus cavity. The sizes of the perforated membranes were measured and recorded. CBCT scans were taken at multiple time points after the surgery to visualize and trace the ejected material. In addition, the time from when the bone graft substitute was delivered to the sinus until the CBCT scans were taken was recorded. The expelled bone graft particles migrated to the ostium along the sinus wall immediately after MSA on CBCT images taken immediately after the surgery. No displaced graft particles were observed in the maxillary sinus on CBCT scans after 1 week. The CBCT scans at 6 months showed no unusual radiographic images. Within the limitations of the case reports, tomographic imaging revealed an MCC system that allows displaced graft particles to be ventilated into the ostium very early during MSA healing and not stagnate in the maxillary sinus.
Keywords: Schneiderian membrane; cone-beam computed tomography; guided bone regeneration; maxillary sinus augmentation; mucociliary clearance.